We was told to make a binary search with the class Recursion. However I'm stuck as the recursion isn't working properly according to my professor(Didn't elaborate when I asked for help) and been working with a fellow student. We come to the conclusion of needing int count but I'm not sure where or how to implement it. Java isn't my strongest language so a guide or hint would be very helpful.
public class Recursive {
public int BinarySearch(int x[], int target, int low, int high)
{
if (low >= high) return -1;
int mid = (low + high)/2;
if (x[mid] > target)
return BinarySearch(x, target, low, mid-1);
else if (x[mid] < target)
return BinarySearch(x, target, mid+1, high); ;
return mid;
}
public int firstNnumber(int n)
{
if (n < 1) return 0;
return firstNnumber(n-1) + n;
}
public int firstNnumber2(int n)
{
if (n==1) return 1;
if (n==2) return 3;
boolean even = (n%2 == 0);
n /= 2;
if (even)
{
return 2*firstNnumber2(n) + n*n;
}
else
return 2*firstNnumber2(n) + (n + 1)*(1+n);
}
public int gaussian(int n)
{
return n*(n+1)/2;
}
static public void main(String [] args)
{
Recursive r = new Recursive();
System.out.println("By Gussain, Sum of first 100000 integers=" + r.gaussian(10000));
System.out.println("By recurssion 2, Sum of first 100000 integers=" + r.firstNnumber2(6));
}
}
This is what is printed, I don't understand what's the problem with my code.
By Gussain, Sum of first 100000 integers=50005000 By recurssion 2, Sum of first 100000 integers=21
your are calling with the wrong params, try calling with
static public void main(String [] args){
Recursive r = new Recursive();
System.out.println("By Gussain, Sum of first 100000 integers=" + r.gaussian(10000));
System.out.println("By recurssion 2, Sum of first 100000 integers=" + r.firstNnumber2(10000));
}